In a system comprising a managing centre having a main database, and a plurality of subscribers each one having a subscriber's database over a wide territory, it is known to send data by phone or hertz route to update the database of these subscribers. These messages address, either to all the subscribers, or to a particular subscriber, that is to say, that they contain a subscribed module address.
As some systems of this type do not use return path towards the managing centre such as by modem for example, it is difficult to know if the sent data have arrived correctly. In this way, it is obliged to repeat these messages periodically in order to ensure that the message has arrived property at destination at least once.
One can easily imagine what the consequence is in a system managing a large number of subscribers, for example 2 to 3 million, the repetition of these messages being able to saturate rapidly the transmission capacity.
In a system of this type, the transmission channel is used more for transmission of useful data such as audio, video or data and managing data, for subscriber databases, and can occupy only a very limited bandwidth.
Such a system is described in the European patent EP 0 616 714, and treats the problem of the updating of a database defined in a smart card. The controls are of simple type and are all destined to enter data in this database. Even if this structure has an advantage on the previous solutions, that is to say based on a structure fixed by the supplier of the software, it do not permit the personalization or special processing.
Another example of the limits of the existing addressing is disclosed in EP 0 491 069. Each database includes a single identifier used to address this database. Thus, when a large number of databases must be updated, they must be addressed sequentially.
One realizes that one is rapidly limited if one wants to use more sophisticated functions, for example to offer one month of free subscription for a new channel to all the subscribers having subscribed for at least one year. In such a case, according to the present transmission technique, one determines on the main database in the managing centre, the list of subscribers answering this criterion, and one formats and then sends on the network a message to each chosen subscriber, a message containing the address of the addressee.
One must not forget that these messages must be repeated periodically to assure that each subscriber has the possibility to receive it.
At present, such functions are not easily possible because they can completely saturate the system with the transmission of managing messages. The specific addressing is therefore used for initialising a subscriber or to update the same, following a call to the management centre.
When one considers the subscriber databases according to the prior art, one can see that these databases contain only information allowing the access to transmissions broadcasted. Said information or data called “systems” such as the subscriber number, are memorized independently. It is based on these data-systems that one determines if a message is addressed to the considered database. No request inside of the database is made, the test using only the systems information.